Until recently, the so-called Ashy-tailed Swift was considered one of the more widespread species of Chaetura swifts found solely in the Neotropics. However, within the last two decades new research has demonstrated that the two subspecies included within Ashy-tailed Swift were not only different species, but that the form breeding in eastern Venezuela was best treated as a subspecies of Vaux’s Swift (Chaetura vauxi). This left Chaetura meridionalis, which breeds in southeastern South America in the austral summer, and winters principally in northern South America, in need of a new vernacular name. Sick’s Swift commemorates the German-born ornithologist, Helmut Sick, who spent most of his adult life in Brazil studying the country’s birdlife. This mid-sized Chaetura is most distinctive on account of its shape, short-tailed with a bulging midwing; the plumage is entirely brown. In terms of its relationships, it seems that Sick’s Swift is perhaps more closely related to the North American-breeding Chimney Swift (Chaetura pelagica) than to the Vaux’s Swift.